Process of treating and forming pipe



May 15, 192 1,669,768

7 G. C. MARTIN PROCESS OF TREATING AND FORMING PIPE Filed Nov. 8. 1926INVENTOR': I GCOZYG B) ATTORNEYS.

Patented May 15, 1928.

UNITED STATES GEORGE C. MARTIN, OF LOS .ANGELES, CALIFORNIA.

PROCESS OF TREATING ANDIORMI NG PIPE.

Application filed November 8, 1926. Serial No. 147,089.

This invention relates to a process and means of treating and formingpipe, such as concrete pipe, in such a manner as to provide a pipe whichhas great resistance to percolation of water or other liquids there-;through.

The invention has for an object the provision of a process and meanswhereby pipe can be made comparatively water-resisting in a simple andinexpensive manner and within a minimum of time.

In practicing the invention I may provide any form of pipe makingmachine which utilizes an outer mould, and a member within said mouldadapted to act upon the material for making the pipe, which will forcethe material into pipe form.. Preferably, this member consists of arotary and reciprocal packer head, which will densely pack the pipemaking material through both rotation and reciprocation thereof. Afterthe pipe has been formed, I then again lower the packer head within thepipe, and make a second run of said head, and while the .said packerhead is revolving pour a water-proof material such as asphalt,asphaltum, a waterproof cement or the like upon said packer head. Whenthe ,water-proof'material is cement, the cement preferably contains somemineral Water carrying body, such as diatomaceous earth. The packer headwill then force in one embodiment of the invention the water-proofmaterial into the surface of the pipe already formed in such a manner asto plaster the inner wall of said pipe. In this connection, it isevident that the packer head, due to its rotation and packing of thepipe making material during the first run or initial making of the pipe,will draw some of the cement in the pipe making material, if said pipemaking material is concrete, to the surface of the pipe, and

when the second run is made of the packer head with, for instance, thewater-proof cement or diatomaceous earth with cement and sand pouredthereon, the cement originally drawn to the surface of the pipe willunite with the waterproof cement and sand. This process of forming thepipe must be distinguished from that process of making pipe which is ofordinary practice when diatomaceous earth is used, inthis, that by theordinary practice the diatomaceous earth is mixed throughout the body ofthe pipe. The diatomaceous earth has four valuable qualities when mixedwith concrete: First,

highly resistant to acids and gases. However, if diatomaceous earth ismixed in any quantity with the concrete over a few per cent it weakensthe concrete because it of itself has no great strength. With myprocess, however, I apply some water-proof means such as asphalt,or.water-pr00f cement or cement with diatomaceous earth or othermineral-carrying body, to the inner surface of the pipe which hasalready been molded out of concrete having the full strength of wellmixed sand, rock and cement, and when. this asphalt or water-proofcement or cement with diatomaceous earth is troweled within the surfaceof the pipe it' makes the pipe resistant to percolation. It is not ofany great importance that this inside plaster bears as great strength asthe concrete pipe, and therefore a'mix richer in diatomaceous earth maybe used than would be possible in the main body of the pipe. Pipe may bemade by practice of this process which has all the strength of the bestconcrete pipe, and still be practically free from percolation of waterwhich maycause it to leak or weaken it. Naturally the second trowelingof the concrete pipe makes it denser. It has been found that theaddition of diatomaceous earth to cement makes the cement ten times asresistant to percolation of water as ordi- I nary cement.

Other objects of the invention will be detailed as the descriptionthereof proceeds, and as illustrating a means for carrying out theinvention I have prepared a drawing in which the figure is a sideelevation of a pipe making machine.

Referring now with particularity to the drawing, 1 may say that theshowing thereof has been fully described in my pending application forpipe making machine filed in the United States Patent Ofiice October 26,1926, Serial No. 144,263. To briefly describe this machine, althoughother forms of machines are equally adaptable for carrying out theprocess, I have provided a base or foundation l upon which the pipemaking machine designated as A is mounted. This machine A includesframework a which has uprights Q and cros members 3 to properly bracethe same, and which framework is so formed as to bestv carry the pipemaking device. 1n the present instance such pipe making device includesa packer head [1 adapted to be rotated by means c and likewise elevatedor lowered by means (I and c. The stand 1. is adapted to accommodate aturntable upon which turntable may be mounted an outer mould f/ and aninner mould it. This outer mould carries at one end a hopper and theopposite end of said mould is formed with a bell end -t adapted tocooperate with the inner mould ll. By turnim the turntable f the mould 1may be brought into such a position as to receive the packer head I.This packer head includes a casing 5 having a cross member 6, whichcross member is secured to an end of the shaft T. Likewise secured tothe shaft T and above the cross member (3 is a spider S, to which spideris bolted or otherwise secured a pair of trowelers 9. Secured to thespider 8 and above the trowelers are wings or propellers 10, of whichthere may be a pair. The shaft; 7 is provided with angularly relatedsides in the present instance, and is passed through suitable bearings11 and 12 and then received within a. cylinder 13, the upper end of saidshaft being provided with a piston head. Also mounted on said shaft is abevel gear l-t which constitutes a part of the means 0 for rotating thesaid shaft. This gear 14 is adapted to mesh with a second gear 15mounted on a shaft 16. This shaft is suitably carried in hearings in theframework, onev of which bearings isshown at 17. This shatt adapted tobe rotated at variable speed through the medium of one or the other oftwo driven pulleys 18 and 19. These pulley's in each instance areloosely mounted upon the shaft- 16 and carry plate clutch members .20and 21. These plate members form two portions of a clutch 71:. Theshiftable member 22 of said clutch is keyed to the shaft. 16 andsuitable means In is provided for moving the shiftable member intoengagement with one or the other of the said members and 21. A, secondsha ft 123 is secured in bearings .Z-l and which shaft carries pulleys26. 27 and Q8. The pulleys QT and 28 are of large and small diametersrespectively. and the pulley of largest diameter is adapted to cooperatewith the. pulley of small diameter on the shaft 16 and the same is truetor the pulleys l8 and 28. Passed over the pulleys are continuous belts29 and 30 respectively. The pulley 2G is the drive pulley and may beassociated with any source of power.

The means e includes a pump which is driven from the shaft 23 as shownat 31, and suitable piping 32. 34 and communicates with a source ofliquid supply 36 and with the top and bottom portions of the cyl inder13. Valve means 31' controls the passage of the fluid in such a mannerthat the fluid will elevate the piston to raise the shaft 7 when thevalve is in one position, and when the valve is in a second positionallow an exhaustion ot the lluid below the piston to lower the saidshaft T.

In utilizing the device as just described, I lirst lower the packer headto the position as shown in the figure, and concrete is then placed uponthe hopper, the packer head is rotated at a slow speed. until the hellend of the mould is properly tilled, after which the clutch is shiftedto rotate the packer head at a higher speed and draw a little cement tothe inner surface of the concrete. The shaft 7 is their elevated whilethe packer head is rotated at a high speed with the. continualapplication of concrete, so that a pipe is formed. The packer head whilestill rotating is then lowered within the formed pipe and some mineralwater carrying, body such as diatomacctms earth, or any standardwaterproof cement, or any suitable waterprooting materials such asasphalt or the like, plus a cement is then placed within the formed pipeand upon the packer head, and the packer head acts upon the hotbituminous material to plaster this material against the inner surfaceof the pipe. Quite obviously, the cen'ientitious product of thediatomaecous earth and the cement. plus the cement already drawn to thesurface of the formed pipe, will unite or adhere by reason of thepressure exerted by the packer head upon such materials. The result willbe a pipe in which the inner surface will greatly resist the percolationof water or other liquids. The inventor has found that whereas a.concrete pipe may be tested for breaking pressures when new, yet aftersaid pipe has been placed in the ground and used, that liquids will seepthrough the pipe and greatly reduce its strength. The present method,however, prevents this loss of strength in the pipe. Quitev obviously.the outer surface of the pipe might be treated, if desired.

It is obvious that various changes and modifications and variations maybe made in carrying out the process and means of forming the pipe asjust detailed without depart ing from the true spirit of the invention.

Having thus disclosed my invention, I claim and desire to secure byLetters Patent:

1. The process of making \vaterproot'ed molded pipe which consists insubjecting a Wet mixture of cement to trowelling pressure from theinside of the mold toward the outside thereof thereby densely to packthe same and cause the cement; of the mixture to be brought to the innersurface of the pipe, and then applying by trowelling pressure awaterproofing material to the inner surface l Consists in firstsubjecting a moldable sub In testimony whereof, I hai'e signed my 0f thepipe thereby pressingthe same into stance ha-rdens applying aWaterproofing the cement. brought to .the surface by the material on toa surface thereof and-workmiginal trowelling pressure. ing the same intosaid body by trowelling' 10 The process of forming pipe, which pressure.

stance to trowelling pressure to mold it into name to. thisspecifiation. pipe form, then betore the moldablevsub- GEORGE C. MARTIN.

